TM 1-1520-238-23
1-250
Change 2
1.75.
APU OPERATING INSTRUCTIONS – USING EXTERNAL POWER – continued
CAUTION
Use of excessive force to actuate hydrau-
lic hand pump could cause damage to
helicopter components. If actuation of
hand pump is stiff or 3000 psi cannot be
accomplished, this may be an indication
that the utility hydraulic accumulator re-
quires nitrogen servicing (para 1.36).
(2) If pressure is below 2600 psi use hand pump
to increase pressure to 3000 psi. If not, pro-
ceed to step l.
(a) Install pump handle (4) on bellcrank (5).
1 Remove retaining pin (6) and handle
(4) from clip (7).
2 Slide handle (4) over bellcrank (5)
and hand pump to 2600 to 3000 psi.
(b) Stow handle (4) in clip (7).
1 Install handle (4) in clip (7) and insert
retaining pin (6).
CAUTION
Ensure access door R325 is closed and
secured before APU start up. Failure to
comply could result in thermal damage to
aircraft structure.
l. Secure access door R325 (para 2.2).
m. Verify APU enclosure air inlet screen is clean
of FOD (para 15.42).
n. Verify fire extinguisher blowout indicator (8) is
in place.
(1) Check indicator (8) below left engine nacelle.
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